I'm only good at seeing when it looks awkward, but I'm not a great artist myself, so I wouldn't know, sorry. :(

Just keep browsing the gallery, you will find tons of great examples and inspirations.

Thanks for the advice, Syko. :)

Yeah, since I used it the first time it did not came out how it should come out :S Do you have an advice how I could have used it better? Or was it totally unneccessary?

The dithering is quite awkward here, abused a little. It adds a lot of unwanted texture.